Optical backgrounds observed from space are highly variable from extreme ultraviolet to the infrared wavelengths. Variations with solar activity can be more than an order of magnitude. Viewing geometry as well as season, latitude, longitude and time of day produce variations of several orders of magnitude. A group of models is described which includes these effects for all of the important optical emissions observed between 500 A and 10,000 A. Solar and particle sources are considered for atomic, molecular, and Rayleigh and aerosol radiation.